This is close to being a circular argument... Of course it is critical to have the canard stall before the main wing - so why add a high lift device to the canard only? An all flying canard or plain flap/elevator on the canard will pitch the plane up to high angle of attack without stalling the main wing as long as the CG is set for stable flight. But I'm guessing canardlover already has that stuff working for him.

Now if you add something that substantially increases the lift or angle of attack capability of the canard like slotted flaps or slats without doing something for the main wing you do indeed risk the main wing stalling first and making a tail first arrival. Flaps on the main wing would not increase the angle of attack that it is capable of( relative to the aircraft datum), but leading edge devices would, thus my suggestion.

I'm just not really following what, besides the obvious, Allan is suggesting???